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gmon.c revision 1.15.10.1 
      1 /*	$NetBSD: gmon.c,v 1.15.10.1 2002/04/26 17:09:51 he Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 1983, 1992, 1993
      5  *	The Regents of the University of California.  All rights reserved.
      6  *
      7  * Redistribution and use in source and binary forms, with or without
      8  * modification, are permitted provided that the following conditions
      9  * are met:
     10  * 1. Redistributions of source code must retain the above copyright
     11  *    notice, this list of conditions and the following disclaimer.
     12  * 2. Redistributions in binary form must reproduce the above copyright
     13  *    notice, this list of conditions and the following disclaimer in the
     14  *    documentation and/or other materials provided with the distribution.
     15  * 3. All advertising materials mentioning features or use of this software
     16  *    must display the following acknowledgement:
     17  *	This product includes software developed by the University of
     18  *	California, Berkeley and its contributors.
     19  * 4. Neither the name of the University nor the names of its contributors
     20  *    may be used to endorse or promote products derived from this software
     21  *    without specific prior written permission.
     22  *
     23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     33  * SUCH DAMAGE.
     34  */
     35 
     36 #include <sys/cdefs.h>
     37 #if !defined(lint) && defined(LIBC_SCCS)
     38 #if 0
     39 static char sccsid[] = "@(#)gmon.c	8.1 (Berkeley) 6/4/93";
     40 #else
     41 __RCSID("$NetBSD: gmon.c,v 1.15.10.1 2002/04/26 17:09:51 he Exp $");
     42 #endif
     43 #endif
     44 
     45 #include "namespace.h"
     46 #include <sys/param.h>
     47 #include <sys/time.h>
     48 #include <sys/gmon.h>
     49 #include <sys/sysctl.h>
     50 
     51 #include <stdio.h>
     52 #include <stdlib.h>
     53 #include <fcntl.h>
     54 #include <limits.h>
     55 #include <unistd.h>
     56 #include <err.h>
     57 #include "extern.h"
     58 
     59 struct gmonparam _gmonparam = { GMON_PROF_OFF };
     60 
     61 static u_int	s_scale;
     62 /* see profil(2) where this is describe (incorrectly) */
     63 #define		SCALE_1_TO_1	0x10000L
     64 
     65 #define ERR(s) write(STDERR_FILENO, s, sizeof(s))
     66 
     67 void	moncontrol __P((int));
     68 void	monstartup __P((u_long, u_long));
     69 void	_mcleanup __P((void));
     70 static int hertz __P((void));
     71 
     72 void
     73 monstartup(lowpc, highpc)
     74 	u_long lowpc;
     75 	u_long highpc;
     76 {
     77 	long o;
     78 	char *cp;
     79 	struct gmonparam *p = &_gmonparam;
     80 
     81 	/*
     82 	 * round lowpc and highpc to multiples of the density we're using
     83 	 * so the rest of the scaling (here and in gprof) stays in ints.
     84 	 */
     85 	p->lowpc = ROUNDDOWN(lowpc, HISTFRACTION * sizeof(HISTCOUNTER));
     86 	p->highpc = ROUNDUP(highpc, HISTFRACTION * sizeof(HISTCOUNTER));
     87 	p->textsize = p->highpc - p->lowpc;
     88 	p->kcountsize = p->textsize / HISTFRACTION;
     89 	p->hashfraction = HASHFRACTION;
     90 	p->fromssize = p->textsize / p->hashfraction;
     91 	p->tolimit = p->textsize * ARCDENSITY / 100;
     92 	if (p->tolimit < MINARCS)
     93 		p->tolimit = MINARCS;
     94 	else if (p->tolimit > MAXARCS)
     95 		p->tolimit = MAXARCS;
     96 	p->tossize = p->tolimit * sizeof(struct tostruct);
     97 
     98 	cp = sbrk((int)(p->kcountsize + p->fromssize + p->tossize));
     99 	if (cp == (char *)-1) {
    100 		ERR("monstartup: out of memory\n");
    101 		return;
    102 	}
    103 #ifdef notdef
    104 	memset(cp, 0, p->kcountsize + p->fromssize + p->tossize);
    105 #endif
    106 	p->tos = (struct tostruct *)(void *)cp;
    107 	cp += (size_t)p->tossize;
    108 	p->kcount = (u_short *)(void *)cp;
    109 	cp += (size_t)p->kcountsize;
    110 	p->froms = (u_short *)(void *)cp;
    111 
    112 	__minbrk = sbrk(0);
    113 	p->tos[0].link = 0;
    114 
    115 	o = p->highpc - p->lowpc;
    116 	if (p->kcountsize < o) {
    117 #ifndef notdef
    118 		s_scale = ((float)p->kcountsize / o ) * SCALE_1_TO_1;
    119 #else /* avoid floating point */
    120 		int quot = o / p->kcountsize;
    121 
    122 		if (quot >= 0x10000)
    123 			s_scale = 1;
    124 		else if (quot >= 0x100)
    125 			s_scale = 0x10000 / quot;
    126 		else if (o >= 0x800000)
    127 			s_scale = 0x1000000 / (o / (p->kcountsize >> 8));
    128 		else
    129 			s_scale = 0x1000000 / ((o << 8) / p->kcountsize);
    130 #endif
    131 	} else
    132 		s_scale = SCALE_1_TO_1;
    133 
    134 	moncontrol(1);
    135 }
    136 
    137 void
    138 _mcleanup()
    139 {
    140 	int fd;
    141 	int fromindex;
    142 	int endfrom;
    143 	u_long frompc;
    144 	int toindex;
    145 	struct rawarc rawarc;
    146 	struct gmonparam *p = &_gmonparam;
    147 	struct gmonhdr gmonhdr, *hdr;
    148 	struct clockinfo clockinfo;
    149 	int mib[2];
    150 	size_t size;
    151 	char *profdir;
    152 	char *proffile;
    153 	char  buf[PATH_MAX];
    154 	int len = sizeof(buf) - 1;
    155 #ifdef DEBUG
    156 	int log, len;
    157 	char buf2[200];
    158 #endif
    159 
    160 	/*
    161 	 * We disallow writing to the profiling file, if we are a
    162 	 * set{u,g}id program and our effective {u,g}id does not match
    163 	 * our real one.
    164 	 */
    165 	if (issetugid() && (geteuid() != getuid() || getegid() != getgid())) {
    166 		warnx("mcount: Profiling of set{u,g}id binaries is not"
    167 		    " allowed");
    168 		return;
    169 	}
    170 
    171 	if (p->state == GMON_PROF_ERROR)
    172 		ERR("_mcleanup: tos overflow\n");
    173 
    174 	size = sizeof(clockinfo);
    175 	mib[0] = CTL_KERN;
    176 	mib[1] = KERN_CLOCKRATE;
    177 	if (sysctl(mib, 2, &clockinfo, &size, NULL, 0) < 0) {
    178 		/*
    179 		 * Best guess
    180 		 */
    181 		clockinfo.profhz = hertz();
    182 	} else if (clockinfo.profhz == 0) {
    183 		if (clockinfo.hz != 0)
    184 			clockinfo.profhz = clockinfo.hz;
    185 		else
    186 			clockinfo.profhz = hertz();
    187 	}
    188 
    189 	moncontrol(0);
    190 
    191 	if ((profdir = getenv("PROFDIR")) != NULL) {
    192 		extern char *__progname;
    193 		char *s, *t;
    194 		pid_t pid;
    195 		long divisor;
    196 
    197 		/* If PROFDIR contains a null value, no profiling
    198 		   output is produced */
    199 		if (*profdir == '\0') {
    200 			return;
    201 		}
    202 
    203 		t = buf;
    204 		s = profdir;
    205 		while ((*t = *s) != '\0') {
    206 			if (len-- == 0) {
    207 				warnx("_mcleanup: internal buffer overflow, PROFDIR too long");
    208 				return;
    209 			}
    210 			t++;
    211 			s++;
    212 		}
    213 		*t++ = '/';
    214 
    215 		/*
    216 		 * Copy and convert pid from a pid_t to a string.  For
    217 		 * best performance, divisor should be initialized to
    218 		 * the largest power of 10 less than PID_MAX.
    219 		 */
    220 		pid = getpid();
    221 		divisor=10000;
    222 		while (divisor > pid) divisor /= 10;	/* skip leading zeros */
    223 		do {
    224 			*t++ = (char)((pid/divisor) + '0');
    225 			pid %= (pid_t)divisor;
    226 		} while (divisor /= 10);
    227 		*t++ = '.';
    228 
    229 		s = __progname;
    230 		while ((*t++ = *s++) != '\0')
    231 			;
    232 
    233 		proffile = buf;
    234 	} else {
    235 		proffile = "gmon.out";
    236 	}
    237 
    238 	fd = open(proffile , O_CREAT|O_TRUNC|O_WRONLY, 0666);
    239 	if (fd < 0) {
    240 		warn("mcount: Cannot open `%s'", proffile);
    241 		return;
    242 	}
    243 #ifdef DEBUG
    244 	log = open("gmon.log", O_CREAT|O_TRUNC|O_WRONLY, 0664);
    245 	if (log < 0) {
    246 		warn("mcount: Cannot open `gmon.log'");
    247 		return;
    248 	}
    249 	len = snprintf(buf2, sizeof buf2, "[mcleanup1] kcount 0x%x ssiz %d\n",
    250 	    p->kcount, p->kcountsize);
    251 	write(log, buf2, len);
    252 #endif
    253 	hdr = (struct gmonhdr *)&gmonhdr;
    254 	hdr->lpc = p->lowpc;
    255 	hdr->hpc = p->highpc;
    256 	hdr->ncnt = (int)(p->kcountsize + sizeof(gmonhdr));
    257 	hdr->version = GMONVERSION;
    258 	hdr->profrate = clockinfo.profhz;
    259 	(void)write(fd, hdr, sizeof *hdr);
    260 	(void)write(fd, p->kcount, (size_t)p->kcountsize);
    261 	endfrom = (int)(p->fromssize / sizeof(*p->froms));
    262 	for (fromindex = 0; fromindex < endfrom; fromindex++) {
    263 		if (p->froms[fromindex] == 0)
    264 			continue;
    265 
    266 		frompc = p->lowpc;
    267 		frompc += fromindex * p->hashfraction * sizeof(*p->froms);
    268 		for (toindex = p->froms[fromindex]; toindex != 0;
    269 		     toindex = p->tos[toindex].link) {
    270 #ifdef DEBUG
    271 			len = snprintf(buf2, sizeof buf2,
    272 			"[mcleanup2] frompc 0x%x selfpc 0x%x count %d\n" ,
    273 				frompc, p->tos[toindex].selfpc,
    274 				p->tos[toindex].count);
    275 			write(log, buf2, len);
    276 #endif
    277 			rawarc.raw_frompc = frompc;
    278 			rawarc.raw_selfpc = p->tos[toindex].selfpc;
    279 			rawarc.raw_count = p->tos[toindex].count;
    280 			write(fd, &rawarc, sizeof rawarc);
    281 		}
    282 	}
    283 	close(fd);
    284 }
    285 
    286 /*
    287  * Control profiling
    288  *	profiling is what mcount checks to see if
    289  *	all the data structures are ready.
    290  */
    291 void
    292 moncontrol(mode)
    293 	int mode;
    294 {
    295 	struct gmonparam *p = &_gmonparam;
    296 
    297 	if (mode) {
    298 		/* start */
    299 		profil((char *)(void *)p->kcount, (size_t)p->kcountsize,
    300 		    p->lowpc, s_scale);
    301 		p->state = GMON_PROF_ON;
    302 	} else {
    303 		/* stop */
    304 		profil(NULL, 0, (u_long)0, 0);
    305 		p->state = GMON_PROF_OFF;
    306 	}
    307 }
    308 
    309 /*
    310  * discover the tick frequency of the machine
    311  * if something goes wrong, we return 0, an impossible hertz.
    312  */
    313 static int
    314 hertz()
    315 {
    316 	struct itimerval tim;
    317 
    318 	tim.it_interval.tv_sec = 0;
    319 	tim.it_interval.tv_usec = 1;
    320 	tim.it_value.tv_sec = 0;
    321 	tim.it_value.tv_usec = 0;
    322 	setitimer(ITIMER_REAL, &tim, 0);
    323 	setitimer(ITIMER_REAL, 0, &tim);
    324 	if (tim.it_interval.tv_usec < 2)
    325 		return(0);
    326 	return (int)(1000000 / tim.it_interval.tv_usec);
    327 }
    328